Remote patient management enables clinicians to follow patient well being without the presence or assistance of medical personnel. Homecare patient management devices, such as communicators or repeaters, collect and forward patient data over a data communications network, such as the Internet, to allow patient well being to be continually monitored and centrally analyzed.
Homecare patient management devices supplement conventional in-clinic programmers used to interrogate patient medical devices, which can include both implantable and external medical devices. Wireless personal patient management devices allow at-home, non-clinical retrieval of patient data through radio frequency interrogation through Bluetooth-compliant, WiFi-compliant, WiMax-compliant, and proprietary wireless communications.
RF interrogation replaces inductive telemetry for implantable medical devices (IMDs) and wired connections for external medical devices (EMDs). Radio frequency-capable (RF) patient management devices, including both homecare patient management devices and advanced programmers for clinical and institutional use, are used to perform RF interrogation of wireless patient medical devices. RF interrogation provided by each such device has a finite and limited signal range, which requires patients to stay physically within range of their patient management devices, particularly for implantable patient medical devices. The limited range can hinder interrogation sessions. In the less formal setting of a home, for instance, a patient might be tempted to move or otherwise inadvertently pass outside the range of a homecare patient management device, thereby interrupting the data exchange session. Moreover, some types of IMDs are designed to preserve battery life by pulsing and modulating bidirectional transaction signal power to the lowest level necessary to successfully transact a data exchange session, so even minor movement can potentially affect the session. Conversely, EMDs need only be close enough to communicate with a patient management device and are generally free of the RF transmission constraints and power management considerations of IMDs.
Other factors can further complicate interrogation sessions. RF interrogation is also susceptible to interference from external sources and environmental factors, such as household appliances or physical obstruction, which can cause a transient break or degradation in transmission signal. Moreover, homecare patient management devices are frequently installed on a bed stand or in a bathroom, which might be inconvenient or unavailable at times when interrogation sessions are scheduled or required, such as in response to caregiver instructions. Thus, reliance on a single interrogation point can cause frustration, particularly if the patient must continually search for an interference-free location within his or her home, or risk missing an interrogation session.
Conventional RF patient management devices generally offer only a single “zone” of interrogation within which the patient and each patient medical device must be physically situated during data exchange sessions. The physical constraint of a single interrogation zone requires physical proximity and near ideal RF conditions. Furthermore, interrupted data exchange sessions must either be rescheduled, or patient data could be lost or not timely relayed to the responsible clinician for proper assessment and action.
U.S. Pat. No. 7,060,031, issued Jun. 13, 2006 to Webb at al. discloses a method and apparatus for remotely programming IMDs. Caregivers generate IMD programming requests at programmers that are remotely connected to a server. The server is securely connected to a remote monitor, which transmits the programming requests to the IMDs through an antenna coupled via a physical connection or wireless telemetry. A plurality of remote monitors and antennas can be connected to the server, which provide multiple devices from which programming requests can be transmitted to an IMD from a single programmer. However, the Webb reference fails to disclose ensuring resilient handoff between physically independent and intelligent antennas that include safeguards against interference or programming session interruptions.
Therefore, there is a need for a user transparent extension to RF interrogation range constraints for remote patient care data exchange. Preferably, such an approach would provide a plurality of interrogation points within a homecare or clinical setting, or other environment, and would support automatic recovery of interrupted sessions with minimal affect on patient actions or privacy.